Today, almost all technical control systems of an automobile include software. Software is considered the spearhead for most technical innovations in recent years. Implemented in control devices, software today controls and adjusts, among other things, motors, transmissions, or safety and comfort systems.
With an increasing number of fields of applications the number of functions executed by control technology rises and thus also their complexity. Today, the rapid development represents a great challenge for automobile manufacturers to keep both quality and the development costs of software on a moderate level. Exemplary life cycles of automotive software approximately 4 years for development, approximately 8 years for production, and approximately 10 years for reproducibility with service. In the years the car is being produced high costs can arise during the administration of variants, primarily caused by different software versions and the heterogeneity of the control hardware used.
One approach the automotive industry has used is to standardize electronic components.
This approach has involved the creation of open standards for electric/electronic (E/E) network structures in the automotive sector, exceeding the boundaries of individual vehicle manufacturers. Illustrative software-technology standards include AUTOSAR, MSR SW DTD, or EAST-EEA.
The software components can represent standard parts designed particularly with regard to their reuse and their closed functionality published by their contractually specified interfaces.
Contractually specified interfaces can be clear descriptions of the behavior required, on the one hand, as well as the offered behavior of software components, on the other hand. Contractually specified interfaces therefore can reduce the interconnection of the system. Thus, software components can be developed, maintained, installed, and combined independently from one another.
Additionally, standardization of the contractually specified interfaces via open standards can ensure that software components are interoperable, which simplifies their reuse. A software component comprising, for example, a part of the control for an antilock braking system (ABS) is thus generally useable, beyond the original equipment manufacturer (OEM).
E/E network structures based on software components can also allow, based on their ability for reuse, a better maintenance and updating ability of the systems and additionally support the increased commercial use of “mass-produced control devices” by the improved decoupling of the software of the control device from the hardware.
From a purely technical standpoint, the contractually specified interfaces of the software components can be taken from publications of a collection of operations, used as a service by another software component, on the one hand, and from the contractual specification of the interface itself, on the other hand.
One analysis of the contractually specified interfaces is to distinguish between service providers and clients. Service providers may be software components, for example, which implement and offer certain services and clients may be software components using certain services of service providers. Here, the contractually specified interface can provide information, which conditions must be fulfilled in order to allow a successful cooperation of service providers and clients. The contents of contractually specified interfaces can be therefore, on the one hand, a contractual description of the things the client requests from the service provider with regard to services and behavior (required interface) and simultaneously a contractual description of the services with a certain behavior the service provider offers under certain conditions (offered interface).
The technical description of a contractually specified interface can be divided into two parts; a functional and a non-functional part. The functional portion may include, for example, names and signatures of operations and data elements that can be exchanged between two software components. The non-functional part primarily may include the behavior of the software components. This includes technical dimensions, such as, for example, the response time in milliseconds [ms] or the consumption of resources in kilobytes [Kb], or for example the precise location and/or the identification of the control device the software component is to be used for.
A software component (service provider) may serve as an example for the description of the non-functional portion and/or for the behavior of a software component with a library of functions for calculating injection amounts of fuel, used by another software component (client), a control component of the electronic fuel injection. Over time the library of functions is improved such that the calculated injection amount becomes ever more precise, however this can negatively effect the time for calculation. This may lead to injection amounts no longer being reported to the control component in real time and the two software components no longer cooperating as desired.
With an increasing complexity of systems, for example a network of control devices, first the importance grows of the entire overview or design view over the system and thus the description of all software components provided in the system and their interactions between each other, including the calculation units available in the system. This description is therefore also called a network layout. For the developer or even better the software designer occupied with the “integration” of software components and the behavior of software components on different control units, the network layout can represent a significant preliminary step for the later implementation, because the network layout can be considered a recommendation for a design plan of a later implementation. By the possibility to correlated networks and network design even with object-oriented concepts it is further possible to continue hereditary principles, e.g., from the object-oriented language into the abstract network view. Thus, the required reuse is not limited to software components but also can include the reuse of networks and network designs.
Based on the description of software components and networks analyses can be prepared evaluating the software components and/or the network design with regard to their features. For example, from the descriptions of software components compatibility tests for a successful cooperation of software components can be performed or the assumed response time for messages can be estimated within the system. This way the developer can discover bottlenecks of the execution of important requirements already during the design of the network and can take countermeasures early, i.e. prior to implementation.
Today, developers are supported by model-based networking tools in the drafting or the design of networks.
As a practical matter, there may be different types, variants, or versions of a standard of technical descriptions of software components. Thus, a comparison exclusively on the level of parameters (technical dimension and unit) may not be easily possible, because other formats or additional or changed parameters may be included in the descriptions of the software components.